Inverter for printed sheets



Dec. 23, 1958 G. H. ALFORD INVERTER FOR PRINTED SHEETS 4 Sheets-Sheet 1 Filed Oct. 26, 1954 27 INVENTOR.

GILBERT H .ALFORD ATTO NEY FIGZ.

Dec. 23, 1958 G. H. ALFORD INVERTER FOR PRINTED SHEETS 4 Sheets-Sheet 2 Filed Oct. 26, 1954 JNVENTOR. GILBERT H.ALFORD MAW/,QW

ATTORNEY.

Dec. 23, 1958 e. H. ALFORD INVERTER FOR PRINTED SHEETS 4 Sheets-Sheet 4 Filed Oct. 26, 1954 GILBERT fiYi fFZmD BMW.

. KWERTER FUR PRlNTEDSI-IEETS Gilbert H. Alford, Baltimore, Md, assignor to Wm. Hollingsworth Machine Co. Inc, Baltimore, Md, a corporation of Maryland Application Gcto'nei' 26, 1954, Serial No. 464,695

2 Claims. (Cl. 214-1) This invention relates to printing machines and more particularly to the handling of the printed stock during and after it has been run through a printing or lithograph press.

In printing on paper and other standard materials in sheet form, and especially when both sides are to be printed on, it is recessary for the sheets to be turned completely over or otherwise inverted. To accomplish this, it is customary after the sheets have been printed on one side with the printing facing upwards, to accumulate a pile or stack. When the pile or stack has reached a predetermined quantity or height, it is turned over by any convenient means available, so the sheets may be picked up and printed on the opposite or unprinted face. The method used ordinarily employs hand labor, and even when done by experts in such handling, consumes considerable time and effort. Further there are losses due to the srnudging of the ink, creasing of the paper and misalignment of the sheets. To offset these difficulties and enable the Work to be done more expeditiously and effectively, a mechanical turner is provided by this invention, to receive the printed sheets, stack them accurately and at the appropriate time and location reverse or invert them as a whole, ready for the second printing. While mechanical devices have been developed to partly accomplish this function, they have usually operated under physical efforts of the machine attendant without intervening mechanisms. The general nature of the devices is based on trunnion construction that renders them more or less dangerous and limit the possibilities of their efficient use. In this invention, the mechanisms employed in its design enable the operation of turning over the printed sheets in stacks actuated under power easily controlled, and embodied in a single unit. It also enables the stack of sheets to be aligned evenly so that when reversed or inverted they will be accurately located and ready for printing on the side opposite to the first printing thereon.

The invention has for its object the provision of a new and improved mechanical inverter for a stack of printed sheets, that will avoid one or more of the disadvantages and limitations of the prior art.

Another object of the invention is to provide a new and improved mechanical inverter for a stack of printed sheets that will include a mechanism for aligning the stack during the operation of reversing the faces of the sheets and arranging them for further printing.

A further object of this invention is to provide a new and improved printers? turner for receiving a stack of printing sheets horizontally disposed on a pallet, holding them securely, aligning them evenly, rotating them 180 so their opposite sides will be faced upwardly ready for transfer to a printing press.

Other objects will become apparent as the invention is more fully explained.

For a general understanding of this invention, its objects, principles and mode of operation, reference is made to the accompanying drawings. These drawings s. cc

are intended to portray a preferred form of the invention, and are explained in the following description.

In the drawings:

Figure 1 is a side elevation of printing sheet inverter unit embodying this invention;

Figure 2 is an end view of the carriage taken along line 2-2 of Figure 1, shown in this embodiment;

Figure 3 is a diagrammatic outline of the mechanism for operating the platforms used in this embodiment, the left-hand diagram indicates the movement of the platforms towards one another, while the right hand diagram shows the movement of the platforms away from each other;

Figure 4 is a detail in perspective of the main shaft for rotating the carriage;

Figure 5 is a perspective view of the base framework used for this embodiment;

Figure 6 is a side elevation detail of the rack and gear and cylinder used in the mechanism from rotating the main shaft;

Figure 7 is a perspective view of the carriage and platforms with the drive cables, pulleys, chainlock and alignment gate omitted;

Figure 8 is a plan view of the lower platform taken on line 8-8 of Figure 7; j

Figure 9 is a perspective detail of the lower platform together with the cylinder and cable mechanism for operating the platforms;

Figure 10 is an end view of the base framework; and

Figure 11 is a perspective detail of the gate used for aligning the stack of printing sheets loaded on the platforms, which are indicated in position on the skids or pallets, the platforms being omitted to make the use of the structure clearer. v

Similar reference numbers relate throughout the drawings.

The inversion machine illustrated in the drawings consists ofa base framework 10 fabricated preferably of structural metal members welded together. The angle irons 11 forming the foundation and disposed to the same parts longitudinally are spaced apart and at the rear of the machine joined together with cross-member angles 12. In addition a pair of spaced brackets 13 include members which rise at converging angles and are connected to horizontal plates 14. These plates 14 are bolted to and support a pair of rectangular journal blocks 15 containing journals which hold a hollow rotatable shaft 16 extending axially through them. A metal support 17 bridges the brackets exteriorly and is slotted at 19 to guide a gear rack 18 in its reciprocating travel. An idler gear 20 confined within a box 21 rotates on a rod 56 suitably journalled in holes 57 in brackets 13 and meshing with the rack 18 also guides the latter and with its walls keeps the rack from jumping off sidewise. The rectangular and narrow box 21 is also supported from the brackets 13 and by the shaft 16 to which a driven gear 22 is keyed. The gear 22 runs between the walls of the box 21 and is rotated by the gear rack 18 as the latter is reciprocated. The rack is designed to rotate the gear 22 and shaft 16 through a circle of 360 and then reverse the direction. The operation of the rack 18 is brought about by a hydraulic cylinder 23 supported on a plate 24 welded to one of the longitudinal angle irons 11 rigidly. Bolts or other conventional holding means are used to removably fasten the cylinder 23 to the plate 24. Piping 25 connects the cylinder 23 with the hydraulic system available (but not indicated in the drawings) and is controlled. by the valves 29. Hydraulic piping 27 passes through the hollow shaft 16 and through flexible connections serves the cylinder 28 for actuating the platform mechanism to be described. The piping 27 is controlled by valves 26 located at some convenient point. The piping 27 is coni 16 extends.

nected to the hydraulic system available. The unit includes a carriage 30 supported by the shaft 16 and rotatable through 360 from a vertical position and returnable to the same plane. The carriage is constructed with a rear panel 31 extending its whole length and having on the central rear area an enlarged disc1ike hoss 58, in the middle of which is an opening through which the hollow shaft The shaft is keyed to the. carriage and conveys the piping 27 to the platform cylinder 28. v The panel is surmounted throughout the greater part of its length by a pair of spaced walls32 formed with exterior longitudinal grooves 33 and interior ones 38 serving as guides and end slots 34 adapted to receive and journal V-groove cable pulleys 35. The space 36 between the walls 32 serves as a chamber for the hydraulic cylinder 28, and the shelf 36 that supports it. The shelf 36 is secured to the panel 31 and is located close to the lower end of the carriage. A back frame 39 also moves in the space 36 guided reciprocatably in the grooves 38. This back frame 39 has a projecting arm 40 extending from it and arranged for the attachment of the piston rod 41 of the cylinder 28 to operate it. A lower (normally horizontal) platform 42 with side walls 43 is designed to support a stack of paper sheets 44 on skid 49 piled on it when the carriage is horizontally disposed. The rear wall 45 of this platform is integrated with the back frame 39. The platform extends out from the front of the carriage as indicated in Figure 7, and is preferably of checkered plate with no wall to obstruct the movement of the stack of paper at the front. In addition the frame 39 has a pair of-rearwardly projecting clamp lugs 46 adapted to fasten on to endless cables or chains 47. The use of cables or chains with pulleys or gears to carry such is optional construction and subject to the judgment and preferences of the designer and is part of this invention.

An upper platform 48 parallel and similar in general structure to the lower platform 42 but inverted with its side walls 62 facing downwards to hold a skid 49 from sidewise movement is mounted on the carriage. Its rear wall 50 is slotted at 51 to engage in the exterior grooves 33 of the carriage so as to be guided thereby when reciprocated. Side posts 52 extend down from the rear wall 50 on both sides. They are also slotted to run in the grooves 33 and limit the movement of the platforms so they will not approach each other too closely. Clamp lugs 53 extend from the posts rearwardly and exterior to the carriage and are attachable to the cables 47 on the outside runs thereof. The arrangement of the sets of clamps 46 and 53 is such that, when the cables are moving in one direction, the platforms move toward each other and, when the direction of travel of the cables is reversed, the platforms move away from each other. A chain and lever tightener mechanism 54 is used to lock the front ends of the upper and lower platforms.

The operation of the unit is generally as follows. It is located adjacent a printing press with its carriage 30 vertically disposed and the platforms 42 and 48 separated to their travel limits. The papers 44 as printed are laid on a skid 49 on the platform that is the lowest until they are stacked to a suitable height. Then the operator opens the valves 26 and actuates the piston in the hydraulic cylinder 28 with its piston rod 41. This causes the platforms to approach each other and clamp the stack of papers with considerable pressure. Then to lock the platforms, the chain and lever mechanism 54 is attached and fastened securely to them and tightened. The turn table cylinder 23 is then operated by its valves 29. The piston rod of this cylinder 23 propels the gear rack 18, which runs on the idler gear and is guided by the box 21 and rotates the driven gear 22 in the latter, and rotates the shaft 16. This revolves the carriage 30, until it has travelled 90 degrees or to a horizontal position, and by the operation of the valves 29 stopped there. The chain mechanism 54 is then loosened by the operator. Then the user controls the valves 26 to loosen up on the platforms and stack of sheets they hold. This allows the stack to drift downward so that its sheets of paper come up against the aligning gate 55 and settle evenly with each other on it. Then the valves 26 are operated to make the platforms clamp the stack tightly, while the operator secures the chain mechanism 54 again. The hydraulic cylinder 23 is then operated to continue to the rotary movement of the carriage in the same direction until the platforms and stack of paper sheets become inverted or 180 from the first position. The valves are then placed in position to hold the platforms and carriage until the paper is to be removed. In the removal of the stack of paper sheets, the chain mechanism is detached and the platform valves are manipulated to separate the platforms and bring to a stop the one underneath at the level of the foundation angles 11, close to the floor. A fork truck is then run up to the lower platform and its fork inserted under the skid with the stack of paper thereon, and loaded. The truck removes the stack of paper to the press that is to print the unprinted side or if the printing has been completed, to its delivery point for distribution. The gate 55 is formed of vertical slats 59 spaced apart and joined across by horizontal slats 60 to support them. The end portions of the slats 60 are offset and bolted to one wall 32 of the carriage and rigidly secured to it.

The unit has the advantage of being able to handle relatively large stacks of printing sheets, and does so quickly and effectively. The stacks are properly aligned and when ready for removal are placed where a fork truck can readily manage them. No handling by individuals is necessary during these processes. The structure is relatively simple and can be manufactured economically, and is portable.

The positions of the platforms can be adjusted so they will suit any ordinary conditions met with in the use of the unit. They may be located close to or greatly separated from each other, by first locating them and then applying the clamps to hold them rigidly to the cables in the positions. The travel of the cables makes the platforms operate together in opposite directions. Thus the travel of the platforms may be varied to suit the conditrons arising.

In explanation of the terms used in this application, the cable and pulleys referred to are intended to be generic enough to include a chain and gear, or a shaft and bevel gear mechanism having the function of pulling the platforms up and down in opposite directions during operation. This causes both platforms to move towards each other to press and hold the paper, and away from the stack of paper when the platforms are reversed. The operations are the same as described when chains and ropes are used and are within the scope of the claims and are a part of this invention.

While but one form of the construction is indicated in the drawings it is not desired to limit this application for letters patent to such form, as it is appreciated that other structures could be designed and manufactured that would employ the same principles and come within the scope of the appended claims.

Having thus described the invention, what is claimed 1. An inversion unit for handling and turning over stacks of fiat sheets located in a horizontal position, each of which said sheets has had an operation performed on one side thereof and is to be subjected to an operation on the other side thereof; said unit comprising a machine having a pair of spaced brackets at one end thereof, a base structure made up of a pair of parallel members to which said brackets are secured, a pair of journals mounted one on each of said brackets, a hollow shaft rotatably mounted in said pair of journals, a carriage rigidly secured to said hollow shaft to be rotated thereby, means for rotating said shaft, step by step, through an arc of and then causing travel of said shaft through the same steps in the reverse order to the original position of said shaft, a pair of platforms carried by said carriage for movement toward each other to clamp said stack of sheets therebetween or away from each other to permit removal of said stack of sheets from such unit; said pair of parallel members extending outwardly and past said carriage and pair of platforms carried by said carriage, said shaft rotating means including a cylinder having a piston reciprocatingly movable therein, a rack secured to said piston, a gear mounted on said hollow shaft and meshing with said rack, and means for controlling the flow of fluid for moving said piston, said means including conduits and connected to the opposite ends of said cylinder, apparatus for moving said platforms toward or away from each other, said carriage including means for guiding the movements of said platforms, a cylinder carried by said carriage and having a piston reciprocatingly mounted therein, a piston rod connected to one of said platforms, conduit structure including flexible parts connected to the opposite ends of the last mentioned cylinder,

a pair of endless flexible members each having'one run connected to one of said platforms and the opposite run connected to the other of said platforms and pulley structure mounted on said carriage to guide said flexible membets.

2. An inversion unit as recited in claim 1, wherein one of said platforms includes posts engaging the platform guiding means on said carriage, and an aligning gate secured to one of said posts.

References Cited in the file of this patent UNITED STATES PATENTS 1,878,994 Abbe Sept. 27, 1932 1,895,640 Norling Jan. 31, 1933 2,325,121 Freeman July 27, 1943 2,520,252 Mutchler Aug. 29, 1950 2,617,635 Ash Nov. 11, 1952 2,627,335 Gedris Feb. 3, 1953 2,645,372 Broersma July 14, 1953 2,656,051 Jenkins Oct, 20, 1953 a 

